Devices were known for ligating lesions by dispensing an elastic band from the outside of an aspiration cylinder of the device over a lesion which has been drawn into the aspiration cylinder. As these devices generally included only one ligating band, the distance between a proximal end of the aspiration cylinder which is coupled to the endoscope and the distal end was relatively small. However, if the user desired to use such a device to ligate multiple lesions, it was necessary to remove the device from the body lumen after each ligation and reload a new ligating band on the aspiration cylinder. This was time consuming and the repeated insertion of the device into the body lumen can cause discomfort to the patient.
Thus, devices have been developed which can dispense each of a plurality of ligating bands over multiple lesions without removing the device from the body to reload. A device for conveniently dispensing ligation bands in a sequential manner is shown in U.S. Pat. No. 5,398,844 to Zaslavsky et at., the entire disclosure of which is incorporated herein by reference. Such a ligating unit may include, for example, a plurality of ligating bands disposed on an outer surface of the aspiration cylinder for release onto lesions within the body by manipulation of a pull cord coupled to the bands.
However, as the number of ligating bands received on the aspiration cylinder has increased, there has been a corresponding increase in the length of the aspiration cylinders. The increased length of the aspiration cylinder can increase discomfort to the patient as the steerability of the distal end of the endoscope is compromised.